Introverts’ and Extroverts’ Brains Really Are Different, According to Science

You’re not imagining it. That extrovert who seems so different from you? It’s because his brain is different.

Introverts are sensitive to dopamine

Why do extroverts like action, but introverts like calm?

It has to do with two powerful chemicals found in our brains — dopamine and acetylcholine, “jolt juices” that hugely impact our behavior.

Dopamine gives us immediate, intense zaps of happiness when we act quickly, take risks, and seek novelty. Acetylcholine, on the other hand, also rewards us, but its effects are more subtle — it makes us feel relaxed, alert, and content.

Extroverts are less sensitive to dopamine, so they need more of it to feel happy. The more they talk, move, and seek new faces, the more they feel dopamine’s pleasant effects.

But we introverts are sensitive to dopamine, so too much of it makes us feel overstimulated and anxious, writes Dr. Marti Olsen Laney in her book, The Introvert Advantage: How to Thrive in an Extrovert World.

However, when we read, concentrate, or use our minds in any way, we feel good because our brains release acetylcholine. Extroverts, on the other hand, hardly register acetylcholine’s gentle happiness bump.

We prefer one side of our nervous system over the other

Everyone’s nervous system has two sides — the sympathetic side, which triggers the “fight, fright, or flight” response, and the parasympathetic side, which is responsible for “rest and digest” mode.

Think of the sympathetic side as hitting the gas pedal and the parasympathetic side as slamming on the brakes.

When your sympathetic system is activated, your body gears up for action. Adrenaline is released, glucose energizes muscles, and oxygen increases. Areas of your brain that control thinking are turned off, although dopamine increases alertness in the back of your brain.

But when you use the parasympathetic side, your muscles relax, energy is stored, and food is metabolized. Acetylcholine increases blood flow and alertness in the front of your brain.

Of course, extroverts and introverts use both sides at different times. But which side do we introverts prefer? You’ve probably already guessed: according to Dr. Laney, the parasympathetic side, which slows us down and calms us.

Information travels a longer pathway through our brains

Ever wonder why, as an introvert, you overthink?

It has to do with how we process stimuli in a different way than extroverts do.

When information from the outside world — like someone’s voice or images on a computer screen — enters an extrovert’s brain, it travels a shorter pathway, passing through areas of the brain where taste, touch, sight, and sound are processed.

This means we process information more thoroughly and deeply. No wonder it sometimes takes us longer to speak, react, or make decisions!

We have more gray matter in the front of our brains

A study published in the Journal of Neuroscience found that introverts had larger, thicker gray matter in their prefrontal cortex, which is the area of the brain that is associated with abstract thought and decision-making. Extroverts had thinner gray matter in that same area. This suggests that we devote more neural resources to abstract thought, while extroverts tend to live in the moment.

So what does this mean?

It means that as an introvert, you were probably born this way — although, of course, your background and experiences play a role in shaping you, too.

It doesn’t mean that you’ll never enjoy a party or seek new experiences, or that an extrovert will never sit still and read a book — we still get to choose what we do.

And of course, “introversion and extroversion are not black and white. No one is completely one way or another — we all must function at times on either side of the continuum,” Dr. Laney reminds us in her book, The Hidden Gifts of the Introverted Child.

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Jenn Granneman is the founder of Introvert, Dear, the popular community for introverts and highly sensitive people. Jenn is an introvert, a highly sensitive person, and an INFJ personality type. She started Introvert, Dear to help other introverts not feel so alone or weird. Look for her first book, The Secret Lives of Introverts: Inside Our Hidden World, in spring 2017. To get personal updates and see the occasional cat picture, follow her on Facebook.

[…] I was just strange. Eventually I learned that being an introvert was common and even was part of neurological processes in my brain. The more I learn about my personality, and how others have learned to […]

[…] that introvert and extrovert brains are not wired the same way. In high stimulus environments, introverts and extroverts respond differently. These environments trigger a dopamine release. Introverts, for example, are more sensitive to […]

Very interesting. I love learning about introverts as an extrovert. It seems as though there are many articles trying to explain being an introvert and how they were always misunderstood and how the world was not designed for them. As an extrovert, I always felt that school was never designed for me. It seemed that the children that were quiet were favored. As a parent of two extroverts and an introvert, I always preach that we need to be patient with both personality. Introverts and extroverts both need to be taught coping skills to survive difficult situations. It takes both type for the world to go round!

[…] writes in her book,The Introvert Advantage: How to Thrive in an Extrovert World, that our brainsreally are different from the brains of extroverts. When information enters the brain of an introvert, it travels a […]

Being an extrovert does not mean that they are not smart;Its a personality type that a person portrays the most, not something that determines how intelligent you are because being an introvert or extrovert doesn’t represents you being smart. This is coming from an introvert btw.

[…] sensitivity to dopamine is that they need less of it to feel happy. Extroverts’ brains run on an energy-spending nervous system, whereas introverts’ brains run on an energy-conserving nervous system. This is […]

[…] Dr. Laney clarifies in her book, The Hidden Gifts of the Introverted Child that “introversion and extroversion are not black and white. No one is completely one way or another – we all must function at times on either side of the continuum”. […]

[…] Dr. Laney clarifies in her book, The Hidden Gifts of the Introverted Child that “introversion and extroversion are not black and white. No one is completely one way or another – we all must function at times on either side of the continuum”. […]

[…] Dr. Laney clarifies in her book, The Hidden Gifts of the Introverted Child that “introversion and extroversion are not black and white. No one is completely one way or another – we all must function at times on either side of the continuum”. […]

[…] They want immediate answers. But that’s not always possible for the thoughtful introvert. We process information deeply and that slows down the rate at which information moves between areas of our brain. We also rely […]

[…] are less sensitive to external rewards like money and status than extroverts are (blame the brain chemical dopamine). Sure, we want a good paycheck, and we’d love to get that promotion, but we often don’t seek […]

The article you cite has nothing to do with what you’re talking about … namely: “Dysregulated affect and impaired social cognition co-occur within disorders marked by abnormalities of the amygdala and mPFC [e.g., major depressive disorder (MDD)] (Curran et al., 1993; Drevets et al., 1997; Hajek et al., 2008; Mayberg, 1997; Price and Drevets, 2010; Savitz and Drevets, 2009b). A leading hypothesis is that variation in amygdala–mPFC circuitry, present within the general population, sets the stage for illness onset through its influence on both affective and social traits (Mayberg, 1997; Price and Drevets, 2010).”